The goal of this is to gain a better understanding of neuronal nicotinic acetylcholine receptors in the ganglia. The knowledge gained in this type of study could aid in understanding of the autonomic nervous system and its function after injury. The aims of this project are: 1.To quantify the regional distribution of the alpha3 subunit of neuronal nicotinic acetylcholine receptors (nAChRs) in autonomic and sensory ganglia and regions of the brain and to determine the ontogenetic profile of the alpha3 subunit protein in the superior cervical ganglion (SCG) using a recently developed alpha3 subunit specific antibody. 2.To qualify the neuronal nicotinic receptor subunit associations in the rat SCG. 3.To examine the regulation of neuronal nAChR subtypes in the SCG by determining alterations in subunit associations and levels of expression of different neuronal nAChRs after axotomy.